legacycentral bbs

after pulling the engine and changing the head gasket. the idle has been acting kinda weird. when i start it up it will idle fine around 1k rpm but once i start to drive and hit boost it starts to idle at 3k if i don't hit boost then it will continue to idle at 1k. if i let it at 3k for about 30sec to 1min then it will drop back down to 1k

Things I've checked:

no vacuum leak as far as i can tell

cleaned iacv when i did the head gasket

if i move the iacv it just moves the idle pionts i.e. 500 and 2k


any ideas would be really helpful

Can you give us a little more background on what you may have moved or changed when the engine was out.

You shouldn't have to adjust the IAC valve top, and could cause things to be off if you do.

Before you did anything, what was it idling at?

hey that sound exactly as the same problem i had
when i play with the idle screw.

i did fix it but since then my idle act weird.
when i set my rpm around 750 and i put my car as i drive on neutral my rpm go higher.

i also experiment my speed needle to jump at a higher rpm
and stick at 3k for few sec even if i release the gas pedal.

its seem to me that the only good setup it so set my engine rev around 600rpm but when i am waiting on a light on the street my rev go lower such as 350 rpm, or if i hit the brake rpm vary. dont know if it's the exact problem but look similar.

when the engine was out heres what i changed:

i did a custom cold air intake

changed from a slant intercooler to a 06 fxt

and plumbed in a catch can


is there any chance the more free flowing intake overwhelms the maf?

legacylok wrote:cleaned iacv when i did the head gasket

I don't think they like to be cleaned. Did mine, started acting up. Now I spray lube into every once in a while, works for a day or two and idles like shit again.

I know you did, but suggest another vac leak check.

I have a catch can setup too. When the hose from the PCV to the can is disconnected I have idle issues...so I 'think' it needs to be a closed system...if that makes sense.

GL,
Td

lol damn looks like i will be doing another vacuum test this weekend

the catch can i have is currently have setup is a closed system

legacylok wrote: the catch can i have is currently have setup is a closed system

Awyeah...the 2 AM sentence structure Been there done that

lol

I should've added:

make sure your hoses are good...if they're old/hard replace 'em. I had one crack underneath...couldn't see it...but felt it luckily.

Lunatech wrote:

legacylok wrote: the catch can i have is currently have setup is a closed system

Awyeah...the 2 AM sentence structure Been there done that

lol

Could be drunk. That'll happen when you're drunk. Or worse. One time I was browsing the latest posts and found one of my own from a while ago when I was drunk on here. Cracked me up because I couldn't even remember making the post!

kimokalihi wrote:
Could be drunk.

Been there done that too

lol good times! and now we know why my car is broken

Done THAT too.! Lol